Conventionally, documents stored in personal computers as data, namely, documents made of characters and charts, etc., are projected expanded on a screen by a projector, in a presentation for describing projects and merchandise. There are projectors having a structure of converting to projection light, image information of documents output from the personal computer, as an image signal, using image converters such as liquid crystal and Micro-Mirror Array.
In recent years, due to the miniaturization of projectors, meetings are often carried out using projectors. In that case, by using a white board as a screen for projection, comments and underline can be directly written down on the white board by a marker, and charts can be created on the whiteboard so as organize a discussion. As this kind of projector, a presentation system using a camera installed in the projector is disclosed in Japanese Patent Application No. H11-305335, FIG. 1.
In a case where charts are created on a whiteboard during meetings, the below methods can be thought of.                (1) Ruled lines are drawn by a marker, and characters, etc., in a frame are also written in by a marker, to a whiteboard.        (2) Ruled lines created by a personal computer is projected by a projector, and characters, etc., in a frame are written in by a marker, to a whiteboard.        (3) Ruled lines created by a personal computer is projected by a projector, and characters, etc., in a frame are written in by input operation of the personal computer.        
However, with method (1), it takes time to draw the ruled lines. With method (2), it is necessary to start up a special application software to draw the ruled lines using the personal computer. With method (3), a plurality of participants surround the whiteboard and create charts, etc., holding markers, and thus can not participate in the discussion, and workability of directly writing down a chart on the screen becomes low.
The present invention has been made in consideration of the above, and the object of the present invention is to provide a projection device and an image obtainment method that is possible to elevate workability.